DATA MANAGEMENT SYSTEM, DATA MANAGEMENT METHOD, CLIENT TERMINAL, SERVER APPARATUS, DATA DECODING APPARATUS, DATA DECODING METHOD, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To reduce damage at the side of the provider of contents data and to safely manage the contents data. SOLUTION: A data management system 300 comprises: a server apparatus 20c for transmitting partial contents Cnwhich is obtained by dividing enciphered contents C for each specific time unit via a network; and a client terminal 10c for watching and listening contents. The client terminal 10c decodes the contents Cnwith a code key Kn-1acquired from partial contents Cn-1as a decoding key, writes Cninto a memory section 2 for displaying the decoded data on a display and generates the code key Knfrom the decoded data written into the memory section 2. The code key Knis used as the decoding key of the next contents Cn+1, is transmitted to a key management server apparatus 24, and is used as the authentication of the client terminal 10c. The server apparatus 20c transmits contents only to the authenticated client terminal 10c next. COPYRIGHT: (C)2004,JPO